fix challenge ordering

Now challenges are ordered on map first by top order value of json file
second by index of array

common/models/challenge.json

@@ -22,6 +22,9 @@
     "order": {
       "type": "number"
     },
+    "suborder": {
+      "type": "number"
+    },
     "dashedName": {
       "type": "string"
     },

seed/index.js

@@ -63,7 +63,8 @@ Challenge.destroyAll(function(err, info) {
           .toLowerCase()
           .replace(/\:/g, '')
           .replace(/\s/g, '-');
-        challenge.order = +('' + order + (index + 1));
+        challenge.order = order;
+        challenge.suborder = index + 1;
         challenge.block = block;
 
         return challenge;

server/boot/challenge.js

@@ -458,7 +458,10 @@ module.exports = function(app) {
       .map(camperCount => numberWithCommas(camperCount));
 
     const query = {
-      order: 'order ASC'
+      order: [
+        'order ASC',
+        'suborder ASC'
+      ]
     };
 
     // create a stream of all the challenges